JPOLE

1. JPOLE Joint Polarization Experiment Similar in concept to JDOP, except with the goal to operationally demonstrate the value of the polarimetric upgrade of the 88D. Multi-seasonal to study both cold and warm season precipitation, with an Intense Observing Period planned for the spring of 2003. Dense ground-based and airborne data collection to support verification. Significant hydrological component is planned. Operational focus to polarimetric rainfall and hydrometeor identification algorithm tests. Goals: -collect data and information that will allow cost/benefit analysis to be performed -demonstrate the utility and feasibility of a polarimetric 88D

2. JPOLE Overview JPOLE will include the first operational test of a polarimetric WSR-88D weather radar. It will also provide an opportunity to investigate many complementary hydrological and meteorological scientific objectives. • The overarching operational goals of JPOLE are to test the engineering design and determine the data quality of a polarimetric WSR-88D radar, demonstrate the utility and feasibility of the radar, and collect data and information that will allow a cost/benefit analysis to be performed. • Plans call for an experiment that will consists of two phases: a multi-seasonal test and evaluation period (to begin in the spring of 2002), and an intense observation period (to begin in the spring of 2003).

3. JPOLE KOUN WSR-88D Radar The open systems development and polarimetric upgrade to the KOUN WSR-88D radar has been a tri-agency effort supported by the NWS, FAA, AFWA. As such the operational objectives of JPOLE are designed to meet the needs of three agencies.

4. JPOLE Operational Demonstration Objectives: The JPOLE Operational Demonstration Objectives and requirements can be broken down into two broad categories • Evaluating the engineering design and data quality of a polarimetric WSR-88D radar • Examining the benefits of polarimetric radar data to operational meteorologists, hydrologists, and aviation users.

5. JPOLE Engineering and Data Quality The Operational Demonstration will provide an opportunity to evaluate critical engineering and data quality issues, for example: • Demonstrate the accuracy of KOUN reflectivity, velocity, and spectrum width through detailed comparisons with conventional WSR-88D radar data • Demonstrate the accuracy of KOUN polarimetric measurements through comparisons with high-quality research polarimetric radar data • Demonstrate that polarimetric precipitation estimation and hydrometeor classification products can be collected with acceptable rotation rates (all previous research results were obtained with relatively slow scan strategies). • Perform tests to assure minimal degradation in VCP times, and no degradation in ground clutter filtering, anomalous propagation filtering, and velocity dealiasing. • Evaluate the value of alternate rHV and LDR scans (and limits to any of the variables).

6. JPOLE Benefits to Operational Users Demonstrate to the hydrological, meteorological, and aviation communities a polarimetric radar’s ability to: • Improve Quantitative Precipitation Estimation (QPE) • Use QPE to improve operational hydrologic forecasts (especially for flash flood events) • Discriminate hail from rain and gauge hail size • Identify precipitation type in winter storms (dry/wet snow, sleet, rain) • Identify biological scatterers (and their effect on wind measurements) • Identify the presence of chaff (and it effect on precipitation measurements) • Identify areas of ground clutter and anomalous propagation • Provide initial conditions and constraints to numerical models for short term forecasts • Investigate the feasibility of identifying aircraft icing conditions

7. JPOLE Training and Data Collection JPOLE will be similar in concept to JDOP, except with the goal to operationally demonstrate the value of the polarimetric upgrade to the WSR-88D radar. • Train operational hydrologists and meteorologists on the use of polarimetric radar data and products (spring of 2001). • Field Phase I: Collect data sets that will allow a detailed analysis of present (non-polarimetric) and future (polarimetric) WSR-88D rainfall and hydrometeor products (to begin in the spring of 2002). • Field Phase II: Collect additional verification data sets using improved infrastructure provided by the addition of community-wide facilities (to begin in the spring of 2003).

8. JPOLE Intense Observation Period Phase II: The proposed JPOLE Intense Observation Period (IOP) will include both cold-season and warm-season observations. • Cold-season: (February-March of 2003) • Focus on hydrometeor identification in winter precipitation and non-precipitating clouds • S-band radar • Ka-band radar • aircraft • Warm-season: (April-June of 2003) • Focus on hydrometeor identification, rain measurements, and hydrologic forecasting for springtime precipitation events • S-band radar • X-band radar • aircraft • surface verification data sets (mesonet, ARS, PicoNet, disdrometer, hail)

9. JPOLE Science Objectives Meteorological: • Improve physical understanding of polarimetric signatures • Verify and improve hydrometeor classification schemes • Develop and verify hydrometeor quantification schemes • Investigate the use of polarimetric hydrometeor information in cloud resolving models Hydrological: • Verify and compare radar rainfall estimates and improve radar rainfall estimators • Investigate DSD variability • Measure streamflow and runoff • Conduct hydrologic modeling

10. JPOLE Scientific Objectives • Improve physical understanding of polarimetric signatures. • Conduct verification and comparison studies of radar rainfall products. Compare conventional and polarimetric radar rainfall estimates. • Collect data that can be used to evaluate the accuracy of operational precipitation and hydrometeor identification algorithms. • Investigate the effect of natural drop size distribution variability on conventional and polarimetric rainfall estimators. • Investigate the effect of drop oscillations and canting angles on conventional and polarimetric rainfall estimators. • Examine the accuracy of hydrometeor classification schemes through detailed comparisons with verification data sets. • Use verification data sets to develop hydrometeor quantification schemes. • Investigate how microphysical information derived from polarimetric radar measurements can be used in cloud resolving models. • Examine the microphysical basis for drop size distribution variability in both cold and warm season precipitation events. • Investigate source of typical overestimation of extreme “cold-process” rain and underestimation of extreme “warm-process” rain. • Investigate how improved precipitation estimates from polarimetric rainfall measurements can be used to initialize hydrologic models. • Measure streamflow and runoff and conduct hydrologic modeling studies. Investigate how input data uncertainties influence flood prediction, the maximum time/space scales required to accurately simulate a flash flood, and the basin characteristics that are most important in transforming rainfall into runoff. • Conduct polarimetric S-band radar intercomparison studies with polarimetric Ka- and X-band radars. • Assess how Ka-band (hydrometeor identification) and X-band (precipitation) measurements can be used to improve interpretation of polarimetric S-band radar data.

11. JPOLE Observational Facilities KVNX LMN KINX Polarimetric radars VCI WSR-88D radars HKL 405 MHz profiler CIM KTLX CIM-KOUN Dual-Doppler KOUN KOUN 100 km range ring PRC 3D lightning mapping network ARS rain gauge network KFDR Blue River basin Dry Creek watershed Small red dots indicate location of Oklahoma mesonet sites

13. JPOLE Proposed Observational Facilities • Research polarimetric radar that can be strategically placed in central Oklahoma to provide both a source of high-quality data that can be used for a comparison with the KOUN radar data (as well as provide input for hydrological distributed modeling studies) • Ka-band and X-band polarimetric radars that can be used for radar comparison studies • Research aircraft to provide in situ microphysical data • Additional rain gauges and disdrometers • Streamflow measurements • Hail chase vehicles

14. JPOLE Future Plans • Coordinate product development with operational meteorologists, hydrologists, and aviation, whose insight and feedback will be of vital importance to the evaluation of the polarimetric WSR-88D products • Introduce polarimetric precipitation accumulation products and modify the HCA to include winter precipitation products (fall of 2001) • Replace NSSL Cimarron polarimetric radar data with that from the KOUN WSR-88D radar (spring of 2002) and begin multi-seasonal data collection • Continue planning for the JPOLE Intense Observational Period (spring of 2003) • Conduct a detailed analysis of non-polarimetric and polarimetric radar products to examine the utility of an operational polarimetric radar

15. Action Items October 2, 2001 NSSL/NWS Operational Demonstration Meeting • Coordinate a presentation to the PMC • Develop a short list of evaluation items for FY 2002 • Develop procedures for meteorological and hydrologic forecasters to evaluate polarimetric products • Develop process for information flow from NWS Headquarters to Region to the local Forecast Office (to coordinate NWS interaction with operational demonstration) • Develop plans for passing hydrologic (Digital Precipitation Array) information to the River Forecast Center.

16. NSSL Polarimetric Radar Algorithms Operational benefits of polarimetric radar: Hydrometeor Classification Precipitation Estimation NSSL currently has three versions of the classification algorithm: 1) RHI - 11 classes (meteorological only) 2) PPI_1 - 5 classes (meteorological only) 3) PPI_2 - 7 classes (meteorological, ground clutter, AP, biological) PPI_2 has been developed to run in real time on NSSL Cimarron polarimetric radar data. After some additional testing, it was delivered to the NWS in late May of 2001.

17. Hydrometeor Classification Algorithm The real-time HCA was delivered to the Norman, OK NWS office in May of 2001. It has 7 classes (meteorological, ground clutter, AP, biological) and is currently running on data from the NSSL Cimarron polarimetric radar. May 6, 2001 Light Rain Moderate Rain Heavy Rain Hail Big Drops AP Birds/Insects

18. Hydrometeor Classification - PPI_1 Algorithm Reflectivity (dBZ) Differential Reflectivity (dB) Specific Differential Phase (deg/km) Classification Rain/Hail Heavy Rain Moderate Rain Light Rain Large Drops

19. Hydrometeor Classification - PPI_2 Algorithm Identification and Removal of AP and Biological Scatterers An extensive region of AP and biological scatterers (birds) was identified and removed. Meteorological data were then classified and put into five categories: Rain/Hail, Heavy Rain, Moderate Rain, Light Rain, and Large Drops.

20. Hydrometeor Classification - RHI Algorithm Radar Reflectivity Hydrometeor Classification RHI Algorithm Light Rain Moderate Rain Heavy Rain Large Drops Rain/Hail Hydrometeor Classification Graupel/Small Hail Hail Dry Snow Wet Snow Horizontal Ice Vertical Ice